1. Field of the Invention
The present invention relates to a light source unit and a projector including the same.
2. Description of the Related Art
A projector is used at meetings, conferences or else to project information on a personal computer display. As a light source unit of a projector the use of a high intensity discharge lamp such as extra high pressure mercury lamp is known. Such a discharge lamp can realize high luminance with no cost increases but it requires a certain length of time from starting lighting to stably becoming luminous. Further, in place of the discharge lamp, solid light emitting elements such as red, green, blue light emitting diodes (LED) or organic EL element are in practical use. A projector including a light source unit using such a solid light emitting element as a light source can activate at high speed and be environment-friendly.
For instance, Japanese Patent Application Publication No. 2011-95388 discloses a light source unit which comprises a first light emitter including a phosphor to emit a light ray in a green wavelength band, a second light emitter including an LED to emit a light ray in a red wavelength band, and a third light emitter to emit a light ray in a blue wavelength band. The first light emitter uses a blue laser diode as an excitation light source and emits a laser beam to the phosphor to excite it and generate a light ray in a green wavelength band from a fluorescence from the phosphor. The three light emitters each include a condensing lens group to collect the light rays from the phosphor and LEDs for projection. The light source unit converges the color light rays from the three light emitters on a single optical axis and projects red, green, and blue light rays on the optical axis. Thus, a projector incorporating such a light source unit can guide the red, green, and blue light rays from the light source unit to an optical modulator such as DMD to control the gradation of each color light for each pixel and project a color image.
However, the optical elements thereof provided on the optical axis are configured to exert an optical effect on all the color light rays in a traveling direction. Therefore, the light source unit is not capable of individually adjust the traveling directions of the color light rays from the three light emitters.